Circadian rhythm regulates diurnal developmental synaptogenesis via the hypocretin system in vivo
作者单位：Institute of Neuroscience and State Key Laboratory of NeuroscienceShanghai Institutes for Biological SciencesChinese Academy of Sciences
会议名称：《中国神经科学学会第十届全国学术会议》
会议日期：2013年
学科分类：0710[理学-生物学] 07[理学] 071006[理学-神经生物学]
关 键 词：synaptogenesis circadian rhythm development hypocretin transgenic zebrafish retinotectal system two-photon imaging in vivo time-lapse imaging
摘 要：Objective Orcadian rhythm orchestrates a wide variety of physiological and behavioral processes of animals to adapt to cyclic environmental *** the adult brain,circadian clock is capable of regulating the structural plasticity of *** remains unknown whether it can regulate developmental synaptogenesis,a fundamental process for building neural circuits in the developing *** Using in vivo two-photon time-lapse imaging of all the presynaptic puncta on the axon arbor of individual retinal ganglion cells in transgenic zebrafish larvae,we examined the dynamics of retinotectal synaptogenesis across day-night cycles during 4-6 days ***（1） We found that the synaptogenic rate undergoes a diurnal oscillation with a peak at daytime and a trough at nighttime.（2） This diurnal oscillation persists under constant darkness or constant light,indicating the involvement of circadian clock in regulating synaptogenesis.（3） This circadian rhythrnicity in synaptogenesis is due to a higher rate of synapse formation at subjective day than at subjective night,but not the difference of synapse elimination rate.（4）Mechanistically,the hypocretin signaling is required for this circadian regulation of *** Our study reveals an endogenous circadian regulation of synaptogenesis in the developing brain and adds a new line of evidence for the circadian control of developmental processes in living animals.